Bizzare bullet behavior 22-250

Hey gents
I have been working on developing a load for my Remington 700 22-250. It has a 1:14 twist in a 26 inch factory varmint barrel. All my loading was based on my results at 100 yards. I was happy with what I had and then went to the 200 line. My groups went from less than on inch to five inches!!?! No signs of key holed bullets, no change in shooting style, no change in wind, weather or ammo. No scope issues either. I loaded 55 grain hornady fmj bt with 37 grainsreloader 15 and a CCI primer. Bullet just off the lands. Any ideas? Could it destabilize after 100? Doesn't make sense and I've been shooting a long time

Get yourself some Hornady V-maxes and watch that gun work magic out to much further distances. I use the 55gr. with a 1:14 twist with no issues, and this in on a rilfe designed specifically to snuff prarie dogs at long range.

Right on I will make the changes. However, I'm still perplexed by the fact that there was a 500 percent change in accuracy AFTER the 100 line. It should be terrible at 100 as well, but it's actually under an inch. How can the trajectory violently change direction like that. Jacket does not seem to be separating. Clean holes in the paper. I even drew the trajectory on paper. It dosnt make sense to me. If it opened to 200 or even 300 percent larger at 200 I would be more accepting.

As above. Change bullets.
I usually use 50grn Hornady V-max, mainly because they're cheaper than the Noslers.
My Remington 700BDL varmint has a 24 inch barrel, I didn't know they made it with a 26".
I have a 26" barrel on my 220 Swift, but it's a Ruger M-77.

I suspect it's not the weight of the bullet, it's the length. I'd guess they're slowing down enough that they start to wobble. The longer a bullet is, the harder it is to stabilize, so it needs a faster twist. Stabilization is a function of both twist and speed.

My guess, and most posters are doing just that, is the FMJ doesn't have as well balanced core as do the V-Max or even the good old flat base match bullets. It's possible that the stability is affected on the way to the target by tiny core differences.
Just try some V-Max or Nosler BT and you'll probably see a positive difference, if you're doing your part at the bench.

Remember those FMJBT are turned out by the millions, and are not match type bullets.

My older brother was on the U.S.Airforce Sec.Police team at McDill,AFB in the late '70's. They had some of the first match accurized M16's turned out from the USAF armory at Lackland,AFB. These were the first to have free-float tubes.

My brother was one of several individuals tasked with testing an assortment of different lot#s of ammo for use by the team in competiton.

I watched one afternoon as he demo'd some different ammo for the officer in charge of the operation/program.
One lot# of LC-75 ammo shot decent 1.5" groups from a sand-bagged M16 at 100meters. He then directed it at the 300yd target. Watching through the spotting scope, you could see the bullets destabilizing before the 300yd target and look like buckshot patterns of 10-12". The bullets were unbalanced and were diverging in a random pattern.

Another lot# from LC-72 IIRC, drove tacks at 300meters. Around 4" groups for 10shots was the norm, but the 100meter groups appeared the same 1.5".
An entire 18wheeler load of that ammo was sent to Lackland AFB and disbursed throughout the USAF teams. They kicked butt at the Nato World shoot that year. My older brother took 11th.

I've seen similar results with differnent lot#'s of non-fmj bullets too. Particularily Hornady bullets. Explains the occasional lot#'s of "blems" available that otherwise appear "normal"....but at "bargain" prices...

Get yourself some Hornady V-maxes and watch that gun work magic out to much further distances. I use the 55gr. with a 1:14 twist with no issues, and this in on a rilfe designed specifically to snuff prarie dogs at long range.

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What he said......Savage 110, 22-250. 10 power scope. 50gr or 55gr VMAX or Sierra 55gr HPBT. Most FMJ bullets are NOT going to give you the best accuracy.

I suspect it's not the weight of the bullet, it's the length. I'd guess they're slowing down enough that they start to wobble. The longer a bullet is, the harder it is to stabilize, so it needs a faster twist. Stabilization is a function of both twist and speed.

There's a reason most BR bullets are flat based.

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Bullets actually get more stable as they slow down. The only reason that speed matters is to impart the initial spin. The aerodynamic forces on the bullet are proportional to its velocity through the air. These forces are in front of the CG of the bullet and try to upset it. That and the geometry of the bullet are what the spin is fighting against for stability. The geometry is constant, the aero forces are not. The spin on the bullet is relatively constant as it goes down range and if it is enough to stabilize the bullet out of the barrel, it will be more than enough once the aerodynamic upset force decreases as the velocity decreases with range.

The only time you have to worry about bullets losing stability as they go downrange is when you have a bullet that have problems with transonic stability and the bullet slows down into the transonic region. You might get a dynamic wobble, but that is different from going unstable. The inconsistent bases of the typical FMJ bullet lends itself to this type of problem. Not to mention that the inconsistent base also means that they have a tendency to spray a bit from the muzzle as the gases come out from around the base of the bullet unevenly. That will impart a good bit of wobble as well.

ETA: BR bullets are flat based mostly because FB bullets are usually more consistent in the heel area. There is one less step in the manufacturing process so one less step to introduce inconsistency. The BR guys also don't care much about BC so gain no benefit from a boat tail.

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